The National Republican Congressional Committee canceled spending against Rep. Betsy Markey (D) in Colorado’s 4th district for the last week before the election and added $700,000 over three weeks to target Rep. John Salazar (D) in the 3rd district.

The move indicates the NRCC’s growing belief that state Rep. Cory Gardner (R) will defeat Markey, and that state Rep. Scott Tipton (R) has a real race on his hands against Salazar.

The NRCC’s independent expenditure arm polled the district and found Salazar and Tipton tied at 45 percent. Increased spending by the NRCC could help Tipton cross the finish line.

Meanwhile, the NRCC will still be on the air in the 4th district Oct. 8-21. Gardner may not be completely on his own from Oct. 22 to Election Day, as outside groups such as the U.S. Chamber of Commerce and Americans for Prosperity have run ads in the district. EMILY’s List has already been active on Markey’s behalf.

The Democratic Congressional Campaign Committee still had TV time reserved in the 4th district for the last two weeks of the election, but Hotline On Call reported Wednesday that the committee is cutting back its reservation. The DCCC is doing so in several districts around the country.

Elsewhere, in Georgia’s 2nd district, the NRCC has now more than doubled its original ad reservation total in its efforts to knock off Rep. Sanford Bishop (D). Bishop was a late addition to the NRCC target list this cycle, and his southwest Georgia seat has become a symbol of how Republicans have been able to use a strong political environment to bring some lower-tier races on line this fall.

According to a GOP source, the NRCC recently reserved an additional $191,000 in air time in the Columbus and Albany media markets during the last two weeks of the cycle. The committee has now committed $300,000 in the district through Election Day.

The Colorado and Georgia moves also further illustrate how fluid the House landscape remains. Earlier in the cycle, the 4th district was the target for Republicans while it kept an eye on the 3rd district. Now that the 4th district looks even more promising, the 3rd district is the NRCC’s target as the committee sees yet another opportunity against Rep. Ed Perlmutter (D) in the 7th district.

Perlmutter is being challenged by Aurora City Councilor Ryan Frazier (R). The district, which includes the inner Denver suburbs, leans further Democratic than the state’s other two Democratic districts in play.